Correlation of heparan sulfate proteoglycan structure and metabolism with the regulation of cell division

Heparan sulfate proteoglycan (HSPG), a ubiquitous cell surface component in animal cells, is a complex, polyanionic macromolecule consisting of a core protein to which are attached several heparan sulfate (HS) chains. Growing and confluent cultures of a rat hepatocyte cell line were labeled with 35SO42- and the HS in the culture medium, the pericellular matrix, the nucleus, the outer nuclear membrane, and the remaining cytoplasmic pool was purified by DEAE-cellulose chromatography. The HS in all pools from the confluent cells exhibited a higher average charge density that the corresponding pools from the growing cells. Analysis of the mixtures of di- and tetrasaccharides formed by cleavage of HS with nitrous acid showed that the structural features of the HS in each pool were different and were altered significantly when growing cells became confluent